COMPLAINANT

the party who initiates the complaint in an action or proceeding; practically synonymous with petitioner and plaintiff. The appropriate term to use is determined by the nature of the proceeding and the court in which it is instituted. EXAMPLE: John Doe files an employment discrimination complaint with the FCHR. At that stage he is referred to as the "Complainant". John Doe later files suit at DOAH. Where he becomes a "Petitioner". Ultimately, John Doe withdraws his DOAH suit in exchange for going to federal court. Now that he's in the judicial branch, John Doe is known as the "Plaintiff" in his case. Compare accused; defendant; respondent
Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016